Answer:
10) 8 11) 10
Step-by-step explanation:
10)
12-4=8
? = 8
11)
7+2=9
19-9=10
<em>TU</em> = 10
I am assuming you wrote the problem wrong. Is it a^2?
A^2 -4A-21=0
(A-7)(A+3)=0
A=7 A=-3, ignore the negative number because it doesn't make sense if you plug in for a.
length=a+3=7+3=10
Width=7=a
The perimeter would probably be 292 because at+b is 7(9)+10, or 73 and there are 4 sides of a circle, so 73 times 4 is 292.